Fluid-pressure compression or holding device.



J. BOYER.

FLUID PRESSURE COMPRESSION 0R HOLDING DEVICE.

APPLICATION FILED JAN. 4, 1897.

Patented Jan. 2,1912

IXMMHi UNITED STATES PATENT oFFIcE.

JOSEPH BOYER, OF ST. LOUIS, MISSOURI, ASSIGNOR TO CHICAGO PNEUMATIC TOOL COMPANY, A. CORPORATION OF NEW JERSEY.

FLUID-PRESSURE COMPRESSION OR HOLDING DEVICE.

To all whom it may concern.

Be it known that I, JOSEPH Borne, a citizen of the United States, residing at the city of St. Louis, in the State of Missouri, have invented certain new and useful Improvements in Fluid-Pressure Compression or Holding Devices, of which the following is a description, reference being had to the accompanying drawing, forming part of this specification.

' My invention relates. to fluid pressure actuated compression devices or presses and in the present instance, for the purposes of description and illustration, I have shown said inventionlas embodied in that class of devices known as rivet holders or holderson, which are used for holding rivets in position while being hammered down and headed, although, as will be evident, my 'invention is applicable to. compression and holding devices for other purposes.

' the description hereinafter given.

The object of my, invention is to -provide a simple, eflicient and reliable device of the ,character'referred to whose features of advantage and' utility will be apparent from In the accompanylng drawing Figure 1 represents atop plan view of my new rivetholder; Fig. 2 a side elevation, partlyin middle vertical section on line 22 of Fig. 3-; Fig. 3 a side elevation of the left or forward side of the valve casing, being a viewv on the line 33 of Fig. 2, with the cylinder and 'its contents removed instead of shownform of a rivet holder as one embodiment,

without intention of limiting my invention to such particular use.

My new rivet holder, which represents the selected embodiment ofmy invention, consist's, as a whole, of a cylinder containing a piston carrying an enlarged and weighted head exterior to the cylinder at one end, a valveat the opposite end of the cylinder for controlling the admission and exhaust of the Specification of Letters Patent. Application filed January 4, 1897. Sena 1N0. 617,980.

Patented Jan. 2, 1912..

motive fluid to and from the cylinder, and, preferably also, an extension upon the opposite side of the valve from the cylinder and in line with the latter, which carries a centering or bearing point adapted to be placed in contact with a suitable abutment or support to sustain the end thrust as the motive fluid forces the piston in the opposite direction. The cylinder A constitutes the middle portion of the structure and contains the piston B which in the present instance is of approximately the full length of the cylinder, and which carries at its forward end, outside the cylinder, a large'weighted head or block C, in the presefit instance formed integral with the piston, said'head being provided upon its rear face with a deep circular groove or recess D adapted to pass over the forward end of the cylinder A when the piston is moved rearward to its limit of movement as in Fig. 2. The piston B is provided with a central bore E closed at its forward end but opening through the piston at its rear end, after explained.

' Screwed. upon the rear end of the cylinder A is the valve casing F containing the plug valve G having a handle by which it may l i purpose here- I be turned. Screwed into an internally threaded boss F formed upon the forward or left hand side of-the "valve casing F at its center is the rear end of an open-ended tube I which extends forward to a point a'djacent the frontend of thebore E in the piston when the latter is in rearward position. Surrounding this tube I and snugly .fitting between it and the cylinder A is a double-cup leather packing J confined be-- tween washers 'K and L and secured to the rear end of the piston B by screws M M. This packing J serves to pack both the ex terior of the tube I and the interior of the cylinder A. p I

-The valve casing F has formed upon one side near its lower end an internally threaded boss- N intowhich is screweda nipple- O, Fig. 1, over which may be slipped the endof a flexible. tube 'P'leading to the air reservoir or other motive fluid supply. This inlet communicates by an upwardly and in-z wardly extending port Q with the valve 'chamber in the casing F, and opening into said chamber the same horizontal plane I as the upper end ofthe port Q, is a port R shown in the drawings, which is its normal or closed position, this recess or passage T places the port R in communication with the exhaust port S, and consequently opens the interior of the tube I and bore E of the piston to the exhaust. When the valve is turned from normalposition in the direction of the arrow in Fig. 4 the exhaust port S will be closed and the inlet port Q be placed in communication with the port It,

toadmit the motive fluid to the tube I andbore E in the piston, with the result hereafter explained. a In addition to the inlet port Q, above described there is provided a' second inlet port -'U, Figs. 2, 3 and 5, opening into the valve chamber at a point some distance below the ports R and S and upper end of the port Q. Opening through the front wall of the valve chamber in the same horizontal plane as this second inletport U is a port V, Figs.

2, 3 and 5, which communicates with the.

rear end of the piston chamber or interior of the cylinder A outside the central tube I. There is also provided a second exhaust port W opening through the wall .of the valve chamber in the same plane asthe ports U and V, as seen in Figs. 3 and 5, and the valve G is provided, in the same horizontal -pla ne as these three last mentioned ports,

with a second segmental cut-or recess X.

hen the valve ,is in its normal position this recess or passage X places the port V in communication with the exhaust port W, as seen in Fig. 5, so that the rear end of the piston chamber is open to the exhaust. When the valve is turned from normal posit-ion in the direction of the arrow the port W will be first closed and the rear end of the 'piston chamber thereby cut off from theexhaus't, and when the valve has been turned far enough the port V will be placed in communication with the inlet port U, and

the motive fluid be thereby admitted to the rear end of the piston chamberoutside .the central tube 1, for a purpose and with the result hereafter explained.

The valve casing is provided upon its rear side with any internally threaded boss Y into which is screwed a rod or 'pipe Z which carries upon its rear end a' head A' provided with a centering or bearingpoint.

.This rod or pipe Z is employed simply to bridge the. space between the rivet-holder proper, as above described, and the support or abutment which is employed to take the end thrust of the device, and will be of suitable length for the purpose, a number of such rods of varying lengths being pro vided with each holder if desired.

At the extreme opposite end of the structure the head G is provided with a suitable recess or bore to receive the stem of the re movable set B which is provided in its forward face with a recess C .ofsuitable shape to fit the head of the rivet which is to be held'in position for the riveting operation. This set B is temporarily held in place in the head G by a pin D passed through a transverse hole in itsstem and co-incident holes in the head O, as shown in Fig. 1. a j

From the foregoing description of the mechanical construction of nty new rivetholder its operation may be describedas follows: When it is brought to position to cooperate with the first rivet of the series,-

that is, brought substantially into line'between said rivet and the abutment or support against which the rear end; of the holder is to rest, the valve is first turned just sufiiciently to close thezexhaust ports .S and IV and bring the inlet port Q, into communicationwith the port R opening into the rear end of the tube I, Fig. 4, but not sufiiciently to place the second inlet port U in communication with the port V, Fig. 5. Under the proportions shown in the drawings an eighth of a turn of the valve will be proper for this purpose. The result of thus admitting the motive fluid to the tube I and internal bore E of the piston, without admitting itsto the rear end of the. piston chamber proper, outside the tube I, is that the motive fiuid'has but a' comparatively small area of the piston to exert its pressure upon an area equaling in size the,ex-. ternal diameter of the tube LI. This will serve to drive the piston forward with a slight and yielding pressure, which will permit the set D to be-readily fitted over'the rivet head, and the structure adjusted as a whole to exactly the desired position be fore full pressure is turned on preparatory to the riveting operation. .The pressure thus. exerted upon the pistonwillnot be so great but that it may be easily overcome by hand and the piston pressed rearward in the cylinder, to permit disengagement of the set B from the head of the rivet, or any desired adjustment of the device. After the" latter has been adjusted tothe desired position the valve will beturned onward to its limit of movement, say a quarter turn, and

the inlet port U be thereby placed incommunication with the port V opening into the rear end of the piston chamber outside the tube I; The motive fluid thus admitted to the rear end of the piston-chamber will rat exert its pressure upon the full area of the annular endpf the piston B, and the latter will be pressed forward by the motive fluid acting upon its full'area, partly within its of the motive fiuid'and relieve the piston of the pressure which has moved it forward,

thereby allowing the piston and its enlarged head to be pressed rearward and disengaged from the head of the finished rivet, ,and moved into position to cooperate with the next rivet; and this may be the operation of the device if desired. It is preferable, however, to retain the pressure within the central bore of the piston while the device is being moved from one rivet to the next, this pressure, as before explained, being sufficiently yielding to permit the piston to be pressed rearward by. hand and disengaged from one rivet head and readily applied to the next one when the device is moved into line with the latter. .By retaining this yielding pressure upon the piston the adjustment of the device to successive rivets the recess X in the valve G, Fig; 5, is of such size and so located with respect to the ports and W that said ports will be placed in communication with each other, at the backward or returnmovement of the valve, before the valve has reached normal position, and consequently beforethe ports Q and B, Fig. 4, have been cut off from each otherand the ports R and S placed in communication with each other; ,with'the result that when the valve is turned backward from its full forward position the exhaust .from the rear end of the piston chamber behind the annular rear end of the piston will be opened before the inlet of the motive fluid to the central-bore of the piston is cut I off and the exhaust therefrom opened. In the present instance the inlet to the rear end of the piston chamber behind the piston is cut off as soon as the valve is started backward i from its forward position (at a quarter turn) and when it is turned backward approximately half way to. normal 0 sition the exhaust is o ened and the motive fluid from the rear on of the piston chamber behind the piston permitted to escape, while the inlet to the central bore of the'pis- [tonremains open and the exhaust therefrom closed. The valve may be provided with a suitable index to readily indicate to the is materially facilitated, and to this. end

operator this half-way position, and when operation upon one rivet is finished the valve will be turned to this position and left there while the device is adjusted to the next rivet, and be then turned forward again to its limit of movement, to admit full pressure to the piston, as before explained. This feature of my device, consisting in. providing the piston with a plurality ofrearwardly facing pressure areas in succession by a suitable valve, and in which the pressure against one ofthe piston areas may be relieved at will without relieving that against its other area, is a highly advantageous and useful feature of my new device, and it will bev understood that the same principle may be carried furto which the motive fluid may be admitted v ther and the piston be provided with more than two pressure areas if desired, and the admission and exhaust of the motive fluidthereto and therefrom be controlled by a suitable valve for the purpose and in the manner required.

I am aware that it has heretofore been proposed to employ pneumatic rivet-holders thrust of the device when the motive fluid.

forces the piston forward to hold the rivet in position; but in the only form of such device with which I am familiar the'motive fluid is necessarily admitted to the entirepressure area of the piston at once, with the result'that it is unwieldy and awkward to handle, the piston being driven forward with great speed and force, so that the forward end of the piston or the set carried thereby often violently strikes the head of the rivet or the face of the plate adjacent thereto, producing shock and liability of damage; and, further than this, if, when the of the motive fluid its front end, or the device carried thereby to fit over the head. of the rivet, does not strike the latter with exact accuracy, so as to properly fit against and hold it, the piston cannot be pressed rearward by hand to effect the proper ad justment, so that'it isnecessary to turn the valve to exhaust position and release the motive fluid. from the cylinder, and then again try to properly adjust the device and turn on a new supply of'motive .fluid,-and possibly only secure proper adjustment after repeated trials, while in the meantime the rivet has becgme cold. My new rivet-holder embodies a very important advantage over such prior ones in this respect, since, as before explained, the. motive fluid may be piston is so 'driven forward by the admission admitted at first to a comparatively small area of the piston, so that the latter will be pressed forward by a slight and yielding pressure, as though by means of a spring, permitting it to be properly adjusted to the rivet, and moved from one rivet to another with great ease and facility.

I do not herein claim the feature of the enlarged head for a rivet-holder, as I have made the same the subject matter of a divisional application filed on March 30, 1905,

Serial No. 252,992.

. 1 Having thus fully described my invention,

. first to a small pressure area to move the from the larger area without exhaustingit .as well as to the said small area, to

piston forward with a slight and yielding pressure and then to a larger. pressure area as well as to the said small area, to press the piston forward with a-maximum force; substantially as described.

. 2. The combination of a cylinder; a piston fitting therein and provided with a plurality of rearwardly facing pressure areas, said pressure areas being of different sizes, a valve casing secured to and closing one end of the cylinder, and a single valve therein for controlling the admission of motive fluid first to a small pressurearea to move the piston forward with a slight and yielding pressure and then to a larger pressure area as well as to the said small area, to ress the-piston forward with a maximum orce,

and also for exhausting such fluid from said pressure areas in successlon; substantially as described.

3. The combination of a cylinder, a piston fitting therein and'provided with a plurality of rearwardly facing pressure areas, said.

pressure L areas being of different sizes, a valve casing secured to and closing one end of the cylinder, anda single valve-therein for controlling the admission of motive fluid first to a small pressure area to move the piston forward with a slight and yielding pressure and then toa larger pressure area ress the .pistonforward with a maximum orce, and also for exhausting such fluid from said pressure areas in succession, exhausting it from the smaller area; substantially, as described. v

4. The combination of a cylinder, a piston fitting therein and-provided with a plurality of rearwardly facing pressure areas, said pressure areas'being of different sizes, a

valve casing secured to and closing one end of the cylinder, and a single valve therein for controlling the admission of motive fluid first to a small pressure area to move the piston forward with a slight and yielding pressure and then to a larger pressure area as well as to the said small area to press the piston forward with a maximum force and also for exhausting such fluid from the larger area while the fluid is still being admitted to the smaller area; substantially as described.

' 5. The combination of a cylinder, apiston fitting therein and bore closed at its ront end and opening through the rear end of the piston, a valve casing secured to the rear end of the c linder, a tube secured to the forward si e of, said valve casing and-extending into the central bore of the piston, a'packing ring secured to the rear end of the piston and serving to pack the exterior of said tube and the interior of the cylinder, and a valve in the valve casing controlling the inlet of the motive fluid and operable to admit said'fluid in succession to the tube 'within the central bore of the piston and to-the annular rear end-of the piston surrounding said tube, and thereafter simultaneously, for the purpose described.

6. The combination of a cylinder, 2. piston fitting therein and providedwith a central bore closed at its frontend and opening through the rear end of" the piston,a valve. casing securedto the rear end of the cylinder, a tube secured to the forward side of said valve casing and extending into the provided with a central central bore of t-he piston, a" packing ring I seciired to the rearend of the piston an serving to pack the exterior of said tube and the interior of the cylinder, and a valve in the valve casing controlling the inlet of the motive fluid and operable to admit said fluid in succession to the tube within the central bore of the piston and to the annular rear end of the piston surrounding said tube, and thereafter simultaneously, and to exhaust the motive'fiuid from the annular rear end of the piston without exhausting it from ferent pressure areas, said sets being on' different planes, and a plug valve operable in said casing and havmg recesses at different planes corresponding with the planesof the sets of ports; and arranged angularly with relation to. each other to admit and exhaust the motive fluid to and from the pressure areas in succession; substantially as described. I I

8. The combination of the cylinder and a piston having difl'erent sized rearwardly the former controlling the ports Q, RS, and facing pres'sure areas, the valve casing F the latter ths ports U V W, for the purpose provided with the inlet ports Q and U, exdescribed, haust ports S and W,and ports R and V JOSEPH BOYER;

5 communicating with the'difi'erent'pressure Witnesses:

areas of the piston, and thevalve G pr0- ROYAL S. MLELERT, vided with the segmental reces ses T and X,, ALFRED J. DOUGHITI'Y. 

